The Incremental Advantage: MIGRATE TRADITIONAL APPLICATIONS FROM

YOUR ON-PREMISES VMWARE® ENVIRONMENT

TO THE HYBRID CLOUD IN FIVE STEPS

Introduction . . . . . . . . . . . . . . . . . . . . 2

Five Steps to the Hybrid Cloud . . . . . . . . . . 3

Architecture of the Hybrid Cloud . . . . . . . . . 6

Conclusion . . . . . . . . . . . . . . . . . . . . .10

About Rackspace . . . . . . . . . . . . . . . . . 11

CONTENTS

As an IT architect, you will likely be tasked with

migrating some of your traditional (legacy) applications

to a cloud environment that’s hosted by a service

provider . There are two basic options for accomplishing

this migration .

One method is to completely re-architect your traditional

applications for deployment in the public cloud . This

may be a viable option, depending on your budget,

time constraints, compliance concerns, number of

available developers and other technical resources, and

related issues . The key challenge is that re-architecting

traditional applications can be a lengthy, complex

process that eats up valuable development time and

resources—and there’s no upfront testing available to

guarantee that the application will ultimately deliver the

required performance . That’s a lot of investment for an

unclear payoff .

The alternative method is a lower-risk, incremental path

to the hybrid cloud that involves splitting an application

between a hosting provider’s dedicated and public cloud

environments . This incremental approach, described

in detail in this paper, can greatly reduce your time

commitment and the risk involved in migrating your

traditional applications to the public cloud, while still

The Incremental Advantage: MIGRATE TRADITIONAL APPLICATIONS FROM YOUR ON-PREMISES

VMWARE® ENVIRONMENT TO THE HYBRID CLOUD IN FIVE STEPS

giving you the cloud-bursting capabilities and other

cost-saving benefits of the public cloud model .

Your precise path to the hybrid cloud will depend on

the application . In this paper, we assume that you have

an existing VMware environment and are migrating a

three-tier application with separate web, application,

and database components . We further assume that

you’re moving this application to the cloud due to

one or more common requirements, such as elasticity,

performance optimization, security, or cost optimization .

To illustrate the incremental hybrid cloud approach, we’ll

use Rackspace® as the hosting service provider .

The end of the paper includes reference architectures

to describe the eventual hybrid cloud solution . But first,

we’ll detail the following five steps to migrate your

three-tier application to the hybrid cloud:

• Step 1: Profile your application

• Step 2: Examine key application characteristics

• Step 3: Build out the hybrid environment

• Step 4: Perform a proof of concept

• Step 5: Cut over to the hybrid environment

3 Rackspace l The Incremental Advantage

FIVE STEPS TO THE HYBRID CLOUD

The following five steps show how you can move a traditional application—in

this case a three-tier application—to a hybrid cloud environment that connects

a dedicated hosting environment to the public cloud .

Step 1: Profile your application

The first step is to profile your application to understand where it is at in

its lifecycle and how to streamline it for more efficient cloud integration .

You can also identify ways that you might be able to reduce costs through

consolidation, modernization, or other alternatives . Application profiling

typically involves creating a data flow model or diagram that highlights all the

components and processes of your application . The diagram shows how data

flows between the different processes, where data resides, and more .

The purpose of the application profiling process is to understand the

components of your applications and the dependencies within those

components . This information will drive architectural decisions related to which

parts of the application will work in the cloud and which parts will need to be

rebuilt or designed around . It will also help you identify levels of complexity

and risk, and determine whether public cloud, private cloud, virtualization, or

bare-metal infrastructure is the best fit for your application’s components .

A variety of application profiling solutions are available, such as Rackspace’s

one- to three-day Application Profiling Workshop . Another popular option is

Unified Modeling Language (UML), which creates industry standards around

a variety of modeling exercises (learn more at www .uml .org) . One of the most

helpful types of modeling related to hybrid architecture decision-making

is a deployment diagram, which can help you understand which processes

lie on particular servers (learn more at www .agilemodeling .com/artifacts/

deploymentDiagram .htm) .

Step 2: Examine key application characteristics

Once you have completed the first step, you can carefully examine the web

layer of your application for specific characteristics and requirements that will

affect your deployment . Specifically, you will want to examine the nature and

dependencies of each process, and how they interact with each other .

For example, in the web layer of your traditional application you may have

a server that knows something unique about a given client or connection .

That’s a red flag for an application to be deployed in the public cloud because

the web layer operates independently and may not be aware of the failure of

another server or have access to the unique information contained on another

server .

Another key consideration relates to the latencies and tolerances between

processes . If the latency of a switching fabric is too heavy—in other words,

if your application is designed such that all application-oriented processes

4 Rackspace l The Incremental Advantage

must live on the web head—then the processes may need to reside on the

same servers or in close proximity . If not re-architected, this application

characteristic may require a vertical rather than horizontal scaling strategy . You

may also be forced to adopt a two-tier architecture where only your database

traverses the dedicated fabric .

For a more detailed examination of the application characteristics you should

consider before putting even a piece of your application in the public cloud,

read cloud architect Wayne Walls’ five-part blog on the “Pillars of Cloudiness,”

which begins with an examination of parallel computing: www .rackspace .com/

blog/pillars-of-cloudiness-no-1-parallel-computing .

Step 3: Build out the hybrid environment

There are several good options for migrating your traditional application to

a hosted environment, with the most common being image porting and data

migration . As mentioned earlier, we’ll describe this process with Rackspace as

the hosting service provider .

Sizing the hybrid environment

The first step is to use resource monitoring tools to identify the baseline

resource requirements of your application, including the CPU, memory, and

disk requirements . Start by tallying the total resources you have available to

each component of your application in its current state, and then compare that

total resource allotment to trends in resource utilization . Take careful note of

the peak requirements of busy utilization times as well as your most common

baseline .

Having a good understanding of the resource needs and trends of your

application will help you decide how much infrastructure you should deploy

initially . For a large-scale application with notable spikes in utilization, focus

on sizing your dedicated footprint to meet the baseline demand, and where

possible leverage the public cloud for periods of higher utilization . The closer

you tune the environment to match the demand pattern, the more cost savings

you can achieve .

Image porting

The fastest, least-friction method for moving your web front end to a hosted

dedicated environment is to simply move your image files over .

By using your existing VMware tools, along with Dedicated VMware® vCenter

Server™ (Dedicated vCenter) from Rackspace, you can easily move VMDK files

from your data center to Rackspace’s data center . Image porting provides

significant advantages with its ease and simplicity .

Dedicated VMware® vCenter Server™ (Dedicated vCenter)

Dedicated vCenter is a unique offering from Rackspace® that provides access to the vSphere API, so that you can control your hosted virtualized infrastructure using the same tools and processes that you already use to manage your on-premise VMware environment . Most vSphere API-compatible tools, as well as scripts written to automate tasks such as provisioning VMs, will work with Dedicated vCenter .

5 Rackspace l The Incremental Advantage

Data migration

You may be able to use image porting for all or some pieces of your

application; for the remainder, data migration is the most common solution .

Businesses and professional service partners have performed data migrations

for a long time, and many options are available .

In general, you first stand up the new environment and then perform whatever

configurations are necessary to get your application running on the new

environment . You then copy all the unique or dynamic data from your existing

environment to the new environment . While you are checking to make sure

that the new environment is running as expected, the original environment

is still in production . That means there’s a delta—at some point you have to

freeze the current production environment, copy the delta environment, and

flip the switch to have all your data flowing as if the new environment is the

production environment .

Data migrations can be a fairly cumbersome process . For qualifying customers

with easily scriptable solutions such as Linux® web server front ends,

Rackspace relieves much of the difficulty through free, automated script

migrations from its Cloud Movers Team .

The Rackspace Cloud Movers Team migrates your source image data into a

new image template in the Rackspace Public Cloud . This assumes that the

images are already functioning in a way that will work well in the public cloud,

with the image architecture uncoupled and the web server split from the

application servers . If that’s the case, you can simply drop your application and

database layer into Dedicated vCenter through a regular migration, and the

Cloud Movers Team will migrate images into the Rackspace Public Cloud .

The Cloud Movers Team approaches each migration on a case-by-case basis

because not all images are a good fit for this service . The prerequisites for this

service include:

• The source image and the new image in the Public Cloud must be like for

like . For example, the source Microsoft® Windows Server® 2012 image would

be migrated to a new Windows Server 2012 image template .

• The Cloud Movers Team can only migrate images that are based on guest

OSes that are supported by the Rackspace Public Cloud . (See a full list of

currently supported OSes at the bottom of this webpage: www .rackspace .

com/cloud/servers/features .)

With your permission, the Cloud Movers Team logs into your on-premises

servers and stands up the hosted infrastructure to match your own . They then

run scripts on the servers that copy data structures, directory structures, and

application configuration components to the destination on the cloud side . This

data transfer is all done over the wire .

6 Rackspace l The Incremental Advantage

For migrating data to the hosted dedicated environment, you have a few

options . For instance, you might migrate VMDK files and related data over the

wire via a secure VPN . Or, if you have a large data footprint, it may be more

practical to ship a storage array to Rackspace, allowing the data to

be imported directly into the environment without the latency of an over-the-

wire copy .

Leveraging a third-party provider can relieve you of some of the most time-

consuming, granular decision-making, so you can focus on larger architectural

decisions regarding your new hybrid design .

Step 4: Perform a proof of concept

One of the main advantages of moving to the hybrid cloud instead of re-

architecting for the public cloud is that you can perform a proof of concept to

test your application in its new environment before going down the costly and

time-consuming road of re-architecting .

A third-party provider is usually needed to help you perform load testing to

capture the performance metrics you need . The specifics of the load test will

depend on your application . If data doesn’t impact your app performance, one

time-saving possibility is to perform the load testing before copying all your

production data and moving it over to the new environment .

If you’ve implemented scaling groups in your cloud environment, you will want

to verify that the environment is scaling up and down as desired . If it’s not

configured to be automatic, make sure to thoroughly document your process

for manually scaling the application up or down .

Step 5: Cut over to the hybrid environment

In this final step, you get traffic flowing to the new dedicated environment . This

usually involves changing your DNS settings to point them from your existing

IP addresses to the new environment .

If your application will support it, you’ll want to take an incremental approach

in this step to reduce your risk . You may, for instance, want to bleed off some

users before you migrate all of them over to your new environment .

ARCHITECTURE OF THE HYBRID CLOUD

The hybrid cloud model gives you much greater flexibility in deploying your

traditional applications . By splitting your application into separate components

located in the dedicated hosted environment and the public cloud, you can

achieve the cloud-bursting benefits of the public cloud while storing your most

sensitive data and running your performance-hungry database and application

components on dedicated gear .

Profile your application

Examine key application characteristics

Build the hybrid environment

Perform a proof of concept

Cut over to the hybrid environment

5 STEPS TO THE HYBRID CLOUD:

1

2

3

4

5

7 Rackspace l The Incremental Advantage

In our three-tier application example, the application could be split into the

following three tiers:

Tier 1: Front-end web layer

Typically you will want to place the front-end web layer of your application in

the public cloud, which will help enable you to respond rapidly to unexpected

spikes in demand and achieve associated cost-optimization benefits .

The hybrid cloud model enables you to further refine this traditional setup

by splitting the web layer and placing at least some of it in your dedicated

environment . For instance, a PCI-oriented customer could place a product

brochure in the public cloud to take advantage of scalability; however, for

security reasons, the payment processing (shopping cart) portion of the

application would need to be in the dedicated environment (see Figure 1) .

FIGURE 1: HYBRID CLOUD MODEL FOR AN ECOMMERCE SITE

Intrusion Detection System

VPN w/ 2 Factor Authentication

Vulnerability Assessment

Web App Firewall

(HA) F5 Load Balancers

Cloud Servers(Non-PCI, Web)

Dedicated Servers(Non-PCI, Web)

Bursting IntoCloud

Cloud Monitoring

Log Manager

Private

Ecommerce Site

CATALOG DISPLAY

SHOPPING CART

SSLCertificate

RackConnect®

Cloud Files

Visitor

Database Servers

Managed Backup(PCI-Compliant)

EMC® DSAN Storage

CDN

VMware® ESXi Hypervisor

VMware® ESXi Hypervisor

(HA) Dedicated Firewalls

(HA)

(HA)

8 Rackspace l The Incremental Advantage

Your hosting provider will need to provide a way for your dedicated and cloud

servers to communicate . In the Rackspace environment, that’s done with a

solution called RackConnect® that enables you to have both your dedicated

and cloud web servers in the same load balancing pool . RackConnect makes

it easy to eliminate your public cloud servers as needed to meet fluctuating

demands and manage your dedicated servers—all from the same pool .

Other types of hybrid deployments that are spread over wide-area networks or

physically distant facilities are limited by the speed of light, which introduces

latency between the tiers of your application . RackConnect enables you to

achieve extremely low latency by connecting your dedicated environment and

the public cloud within the same data center .

The RackConnect automation system also configures the software firewall on

each of the cloud servers, so that you don’t have to set the software firewall

rules (iptables or Windows Firewall) individually to ensure that the servers

communicate in the way you desire .

RackConnect®

WWW

CLOUD SERVERS

PHYSICAL SERVERS

Cloud FilesServers (Web)

Servers (App) Servers (Web)

Servers (App)

CDN

VMware® ESXi Hypervisor

VMware® ESXi Hypervisor

Internet Routing Switching

Database Servers

Managed Backup(PCI-Compliant)

F5 Load Balancers

Firewalls

(HA)

(HA)

(HA)

(HA)

EMC® DSAN Storage

FIGURE 2: TYPICAL RACKCONNECT HYBRID DEPLOYMENT

RackConnect®-supported network devicesThe RackConnect automation is compatible with any Cisco® ASA firewall (5505 Security+ or better) or F5® Big-IP load balancer . The optimal solution is the F5 Big-IP load balancer, which provides the ability to load balance between the dedicated Rackspace environment and the public cloud .

9 Rackspace l The Incremental Advantage

Figure 2 shows a typical RackConnect hybrid deployment, in which new

greenfield applications or web- and application-layer compute workloads

reside in the public cloud, while high-performance connectivity is maintained

to the backend traditional systems .

Tier 2: Dedicated components

You’ll likely want to have at least some components of your web application

reside in your dedicated environment . If you have a typical front-end Apache™

web server hosting your website, that’s ideal for the public cloud . You could

optimize for cost by splitting a portion of the front-end server traffic so that

the dedicated footprint handles the constant base, and you leverage the cloud

for unexpected traffic spikes . If you have security or compliance concerns, the

single-tenant dedicated environment would be the best fit .

Figure 3 shows how Dedicated vCenter can be used to simplify management

of components within the dedicated environment .

Dedicated vCenter

VMwareHypervisors

vSphereAPI

RackspaceData Center

Production

VMwareHypervisors

vSphereAPI

YourData Center

Your IT Team

Your Toolsand Scripts

FIGURE 3: DEDICATED VCENTER SIMPLIFIES MANAGEMENT ACROSS ON-PREMISE AND HOSTED ENVIRONMENTS

10 Rackspace l The Incremental Advantage

Tier 3: Back-end database

There are a number of issues to consider when determining how to host the

back-end database portion of your application to get the most out of your

resources . Note that whichever method you choose, breaking out part of

the workload to mix VMware with dedicated servers is a seamless process . It

simply comes down to making a deployment decision .

If you find that you’re scaling your database VM to the point where it’s virtually

the only VM running on a hypervisor—or if you’re continually upgrading the

hypervisor to manage one VM—it may make more sense to use a standalone

server in your dedicated environment, which will reduce your overhead and

latency .

Another consideration relates to performance issues, which might come up

if you have multiple database VMs running on a hypervisor that all require

significant disk I/O . In that case, it will likely make more sense to optimize

performance using a bare-metal architecture in your dedicated environment .

Such performance issues could arise at any layer of the application, although

the database is the most common .

CONCLUSION

This white paper describes an incremental path for taking a traditional three-

tier application to the hybrid cloud . This approach provides several advantages

over completely re-architecting the application for the public cloud, including

the potential to shave months off the re-architecting process and reduce risk

by enabling load balancing and testing .

For IT architects charged with finding a cost-effective path to the cloud that

helps protect existing VMware investments, a hybrid cloud may be the best

solution . By combining a dedicated hosting environment with the public cloud,

you can achieve all the benefits of the public cloud—including elasticity and

cost optimization—while also retaining greater control, security, and flexibility

over your deployment architecture .

As one VMware’s largest VSPP partners, Rackspace has expert VMware

Certified Professionals available and experience that comes with managing

over 45,000 VMs . To find out more about how Rackspace can help you take

the first step to the hybrid cloud, take a look at our Application Profiling

Workshop .